Could not find a valid Docker environment with Maven: failed with exception ArrayIndexOutOfBoundsException (1)

[s-lindenau]

Hello, this is a discussion for a potential bug report, or getting assistance with fixing my environment/project setup.

When i run a unit test with a testcontainer, i encounter a strange issue.

• Running the test from my IDE (Intellij -> Junit Run Configuration -> Run all tests), everything works perfectly!
• When i run the same tests with Maven (via the surefire-plugin), my docker environment can't be located.

Software used:
Short summary:
Java 8, JUnit4, Maven 3, Windows 10 Pro, Docker desktop, WSL
Testcontainers version: org.testcontainers:oracle-xe:1.19.8
Surefire plugin version: 2.22.2

mvn --version

Apache Maven 3.3.9 (bb52d8502b132ec0a5a3f4c09453c07478323dc5; 2015-11-10T17:41:47+01:00)
Maven home: ...\apache-maven-3.3.9
Java version: 1.8.0_212, vendor: Oracle Corporation
Java home: ...\jdk1.8.0_212\jre
Default locale: en_US, platform encoding: Cp1252
OS name: "windows 10", version: "10.0", arch: "amd64", family: "dos"

docker version

Client:
 Cloud integration: v1.0.35+desktop.13
 Version:           26.0.0
 API version:       1.45
 Go version:        go1.21.8
 Git commit:        2ae903e
 Built:             Wed Mar 20 15:18:56 2024
 OS/Arch:           windows/amd64
 Context:           default

Server: Docker Desktop 4.29.0 (145265)
 Engine:
  Version:          26.0.0
  API version:      1.45 (minimum version 1.24)
  Go version:       go1.21.8
  Git commit:       8b79278
  Built:            Wed Mar 20 15:18:01 2024
  OS/Arch:          linux/amd64
  Experimental:     false
 containerd:
  Version:          1.6.28
  GitCommit:        ae07eda36dd25f8a1b98dfbf587313b99c0190bb
 runc:
  Version:          1.1.12
  GitCommit:        v1.1.12-0-g51d5e94
 docker-init:
  Version:          0.19.0
  GitCommit:        de40ad0

Pom.xml

<dependency>
	<groupId>org.testcontainers</groupId>
	<artifactId>oracle-xe</artifactId>
	<version>1.19.8</version>
	<scope>test</scope>
</dependency>

The unit test is structured as follows (for legacy reasons a custom Junit4 Runner is used):
@RunWith(MyTestRunner.class)
Where the Runner creates a container as a singleton used by all tests, and then starts it:

        oracleContainer = new OracleContainer("...")
                .withDatabaseName("...")
                .withUsername("...")
                .withPassword("...")
                .withInitScript("...");
        oracleContainer.start();

The error i'm getting:

INFO  o.t.utility.ImageNameSubstitutor - Image name substitution will be performed by: DefaultImageNameSubstitutor (composite of 'ConfigurationFileImageNameSubstitutor' and 'PrefixingImageNameSubstitutor')
INFO  o.t.d.DockerClientProviderStrategy - Loaded org.testcontainers.dockerclient.NpipeSocketClientProviderStrategy from ~/.testcontainers.properties, will try it first
DEBUG o.t.d.DockerClientProviderStrategy - Trying out strategy: NpipeSocketClientProviderStrategy
DEBUG o.t.d.DockerClientProviderStrategy - NpipeSocketClientProviderStrategy: failed with exception ArrayIndexOutOfBoundsException (1)
INFO  o.t.d.DockerMachineClientProviderStrategy - docker-machine executable was not found on PATH ([...])
ERROR o.t.d.DockerClientProviderStrategy - Could not find a valid Docker environment. Please check configuration. Attempted configurations were:
	NpipeSocketClientProviderStrategy: failed with exception ArrayIndexOutOfBoundsException (1)As no valid configuration was found, execution cannot continue.
See https://java.testcontainers.org/on_failure.html for more details.

java.lang.IllegalStateException: Could not find a valid Docker environment. Please see logs and check configuration
	at org.testcontainers.dockerclient.DockerClientProviderStrategy.lambda$getFirstValidStrategy$7(DockerClientProviderStrategy.java:277)
	at java.util.Optional.orElseThrow(Optional.java:290)
	at org.testcontainers.dockerclient.DockerClientProviderStrategy.getFirstValidStrategy(DockerClientProviderStrategy.java:268)
	at org.testcontainers.DockerClientFactory.getOrInitializeStrategy(DockerClientFactory.java:152)
	at org.testcontainers.DockerClientFactory.client(DockerClientFactory.java:194)
	at org.testcontainers.DockerClientFactory$1.getDockerClient(DockerClientFactory.java:106)
	at com.github.dockerjava.api.DockerClientDelegate.authConfig(DockerClientDelegate.java:109)
	at org.testcontainers.containers.GenericContainer.start(GenericContainer.java:329)
	at (Custom Junit Runner)
	at org.apache.maven.surefire.junit4.JUnit4Provider.execute(JUnit4Provider.java:264)
	at org.apache.maven.surefire.junit4.JUnit4Provider.executeTestSet(JUnit4Provider.java:153)
	at org.apache.maven.surefire.junit4.JUnit4Provider.invoke(JUnit4Provider.java:124)

What i've tried:

• Switch to org.testcontainers.dockerclient.EnvironmentAndSystemPropertyClientProviderStrategy in my testcontainers.properties file and provide the docker.host manually as tcp://localhost:2375, but this also fails with the same ArrayIndexOutOfBoundsException (1)

A problem is that the stacktrace of this ArrayIndexOutOfBoundsException is lost in the catch statement of org.testcontainers.dockerclient.DockerClientProviderStrategy#tryOutStrategy, so i'm not quite sure where it fails, and what i could try next to fix it?
Is it an option to add (debug) logging with the entire stacktrace here?

Edit: i managed to attach a debugger to my maven unit test runner, and extract the following stacktrace:

java.lang.ArrayIndexOutOfBoundsException: 1
        at org.testcontainers.shaded.com.github.dockerjava.core.DockerClientConfig.getObjectMapper(DockerClientConfig.java:61)
        at org.testcontainers.shaded.com.github.dockerjava.core.DockerClientConfigDelegate.getObjectMapper(DockerClientConfigDelegate.java:55)
        at org.testcontainers.shaded.com.github.dockerjava.core.DockerClientImpl.withHttpClient(DockerClientImpl.java:228)
        at org.testcontainers.shaded.com.github.dockerjava.core.DockerClientImpl.getInstance(DockerClientImpl.java:211)
        at org.testcontainers.dockerclient.DockerClientProviderStrategy.getClientForConfig(DockerClientProviderStrategy.java:416)
        at org.testcontainers.dockerclient.DockerClientProviderStrategy.getDockerClient(DockerClientProviderStrategy.java:74)
        at org.testcontainers.dockerclient.DockerClientProviderStrategy.tryOutStrategy(DockerClientProviderStrategy.java:292)
        at org.testcontainers.dockerclient.DockerClientProviderStrategy.lambda$getFirstValidStrategy$5(DockerClientProviderStrategy.java:266)
        at java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:174)
        at java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:175)
        at java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:175)
        at java.util.ArrayList$ArrayListSpliterator.tryAdvance(ArrayList.java:1359)
        at java.util.stream.ReferencePipeline.forEachWithCancel(ReferencePipeline.java:126)
        at java.util.stream.AbstractPipeline.copyIntoWithCancel(AbstractPipeline.java:498)
        at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:485)
        at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:471)
        at java.util.stream.FindOps$FindOp.evaluateSequential(FindOps.java:152)
        at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
        at java.util.stream.ReferencePipeline.findFirst(ReferencePipeline.java:464)
        at org.testcontainers.dockerclient.DockerClientProviderStrategy.getFirstValidStrategy(DockerClientProviderStrategy.java:267)
        at org.testcontainers.DockerClientFactory.getOrInitializeStrategy(DockerClientFactory.java:152)
        at org.testcontainers.DockerClientFactory.client(DockerClientFactory.java:194)
        at org.testcontainers.DockerClientFactory$1.getDockerClient(DockerClientFactory.java:106)
        at com.github.dockerjava.api.DockerClientDelegate.authConfig(DockerClientDelegate.java:109)
        at org.testcontainers.containers.GenericContainer.start(GenericContainer.java:329)
        at (Custom Junit Runner)
        at org.apache.maven.surefire.junit4.JUnit4Provider.execute(JUnit4Provider.java:264)
        at org.apache.maven.surefire.junit4.JUnit4Provider.executeTestSet(JUnit4Provider.java:153)
        at org.apache.maven.surefire.junit4.JUnit4Provider.invoke(JUnit4Provider.java:124)
        at org.apache.maven.surefire.booter.ForkedBooter.invokeProviderInSameClassLoader(ForkedBooter.java:200)
        at org.apache.maven.surefire.booter.ForkedBooter.runSuitesInProcess(ForkedBooter.java:153)
        at org.apache.maven.surefire.booter.ForkedBooter.main(ForkedBooter.java:103)

Again, running the tests directly from my IDE can connect to Docker, and the testcontainer is downloaded, started and all test execute just fine connecting to the Oracle database over JDBC running in the container.
In this case it is connecting over the npipe named socket, so that exists and functions.

[s-lindenau]

After debugging my maven runner i noticed that surefire forks into a new process, and that caused some problems with attaching a debugger. So i tried to disable it, and when i disable forking, the tests work, and the exception is gone!

	<plugin>
                <artifactId>maven-surefire-plugin</artifactId>
....
                <configuration>
	                <forkCount>0</forkCount>

In stepping through with the debugger, i end up at org.testcontainers.shaded.com.github.dockerjava.core.DockerClientConfigDelegate, for which the field final DockerClientConfig original; (or the entire Delegate object) somehow isn't available anymore?

Possibly related issue: #2939
Now, ideally, i would not like to disable forking if that is possible. But given the related issue, that might void the intention of my singleton container.

What could be causing this problem?